The invention relates to a continuously operating device for directing pressing or pulling force at an object fed in relation to the device, at that part of the object which is at the location of the device, by using the at least two pairs of rolls or the like belonging to the device, which are at a distance from one another in the direction of movement of the object and through the nips between which the object is arranged to travel, whereby to at least one roll of at least one pair of rolls is connected, supported on the roll and thus rotating with the roll, an actuator effecting a rotary movement concentric with respect to the axis of rotation of the roll, the actuator being in turn arranged to transmit the said rotary movement by mechanical power transmission means to at least one roll of the other pair of rolls.
The type of device mentioned above is known from the Finnish patent 90321 (Vuolle-Apiala). The hydraulic hoses between the hydraulic motor rotating with the roll and the hydraulic aggregate fitted solidly in place outside the roll and acting as the power source of the hydraulic motor are provided with connecting slides due to the parts rotating with respect to one another. Components such as these limit the permitted hydraulic pressure to a relatively low level, which means that sufficiently strong pressing or pulling forces cannot be obtained in all cases.
The object of the invention is to eliminate such disadvantages limiting the hydraulic pressure in known solutions and to achieve a continuously operating device for directing pressing or pulling force at an object or the like fed in relation to the device, which device is structurally as simple as possible, economically priced and consumes little energy, and which device can be used, among others, as a continuously operating press when making finger joints and, for example, as a part of a continuously operating strength-grading device for timber or other similar testing apparatus
To achieve this object it is characteristic of the device relating to the invention that a drive shaft is provided for supplying the driving power of the actuator, which shaft is arranged to rotate concentrically with respect to the axis of rotation of the roll, but independently with respect to the said axis of rotation, and which drive shaft is, on the other hand, arranged to be rotated by a power means.
Further preferable developments of the invention are described in the dependent claims.